KR20130129287A - Turbine rotor and method for producing turbine rotor - Google Patents

Abstract

The turbine rotor 10 which concerns on this invention is equipped with the 1st member and the 2nd member joined to the said 1st member, and the said turbine rotor 10 in which the said 1st, 2nd member extends in the axial direction of a turbine rotor. And an improvement part 16 for welding is formed in the boundary of the said 1st, 2nd member, penetrates the bottom part of the said improvement part 16, and introduces gas into the said turbine rotor 10 inside. The gas introduction hole 18 for sealing is sealed by welding.

Description

Turbine rotor and manufacturing method of turbine rotor {TURBINE ROTOR AND METHOD FOR PRODUCING TURBINE ROTOR}

The present invention relates to a turbine rotor which is formed by joining two different members in the axial direction of the turbine rotor by welding.

This application claims priority in March 23, 2011 based on Japanese Patent Application No. 2011-064657 for which it applied to Japan, and uses the content for it here.

The temperature of the steam which passes through the turbine rotor which comprises a turbine, such as a steam turbine, changes with the position along the axial direction of a turbine rotor. Therefore, as this turbine rotor, what is called the transfer material welding rotor which joined the several plural different members in the axial direction by welding and is conventionally used.

And as a method of welding two members in this transfer material welding rotor, the method of welding so that the surface of the two members which contacted the front-end | tip did not penetrate to the back surface is mentioned (for example, patent document 1 Reference). However, in such a welding only on one side, there exists a possibility that a crack may progress to a welding part from the joint of two members which remain in the back surface. Therefore, in order to prevent the occurrence of such a problem, it is necessary to construct so-called wave welding that penetrates to the back surface of the two members in contact.

Here, in TIG welding generally used for manufacture of a transfer welding rotor, the surface of the member of the side which approaches a welding torch is prevented from oxidation by the inert gas injected from a welding torch. However, when constructing a wave welding, it is necessary to prevent oxidation also about the wave formed in the back side of two members.

By the way, in general wave welding, not only a turbine rotor, as a means of preventing oxidation of a wave, an inert gas is inject | poured on the back side of a member, or a space is formed so that a wave may be surrounded on the back side of a member, and this space is provided. The method of filling inert gas into the inside of the inside is conventionally used (for example, refer patent document 2).

And in the case of a turbine rotor, the cavity part is formed in the back side of a welding part inside a turbine rotor, and the inert gas is previously filled in this cavity part. Here, as a means for supplying an inert gas into the cavity from the outside, an inspection hole formed to reach the cavity from the surface of the member is used. This inspection hole is used for inspecting the finishing state of the back side of a member by inserting a fiber scope or the like into the inspection hole during or after the welding operation. Then, the inert gas is fed into the cavity through this inspection hole.

Japanese Patent Application Laid-open No. 2010-31812 Japanese Patent Application Laid-open No. Hei 8-206830

In the conventional turbine rotor, there is a possibility that stress concentration may occur around the inspection hole formed in the turbine rotor, which is undesirable in strength design. Therefore, there is a need for a turbine rotor in which an inert gas is filled in the cavity without forming an inspection hole and a manufacturing method thereof.

This invention is made | formed in view of such a situation, The objective is the turbine rotor by which two different members contact the tip of two members in the axial direction of a turbine rotor, and welds the quality of the turbine rotor after welding. It is providing the means to fill inert gas inside, without reducing.

The turbine rotor which concerns on this invention is a turbine rotor provided with the 1st member and the 2nd member joined to the said 1st member, and the said 1st, 2nd member extends in the axial direction of a turbine rotor, The said 1st The improvement part for welding is formed in the boundary of a 2nd member, The gas introduction hole for introducing gas into the inside of the said turbine rotor through the bottom part of the said improvement part is sealed by welding, It is characterized by the above-mentioned. do.

In the turbine rotor of the present invention, when welding the first and second members, an inert gas is introduced into the cavity inside the turbine rotor through the gas introduction hole in order to prevent oxidation of the waves generated in the members. According to the present invention, after welding of the first and second members, the weld metal is filled in the gas introduction holes, so that stress concentration hardly occurs in the peripheral portion where the gas introduction holes previously existed. Therefore, the fall of the strength of a turbine rotor can be prevented.

In the turbine rotor of the present invention, the material of the first member is different from that of the second member, and the boundary between the first and second members in the improved portion may be present at either of the two members. .

In the turbine rotor of the present invention, since the boundary between the first and second members in the improvement part is present in one of both members, the gas introduction hole is spaced apart from the boundary of the bottom of the improvement part. It is possible to form in position. In this way, when the gas introduction hole is to be formed at a position spaced apart from the boundary, the drill for processing the hole does not slide at the boundary to lower the positional accuracy of the hole, thereby forming the gas introduction hole at a desired position. can do. Moreover, since the positional accuracy of a hole is high, a hole can be drilled correctly in a predetermined drilling position. Thereby, this hole is reliably blocked when welding a 1st member and a 2nd member.

Moreover, the turbine rotor which concerns on this invention exists in the material of the said 1st member different from the said 2nd member, and the said boundary is biased to the one member with the high hardness among the said 1st, 2nd member.

According to such a structure, a drill can be prevented from being thrown by the member with high hardness, and flowing to the side of the member with low hardness, and a hole can be formed through only the member with low hardness.

Moreover, the turbine rotor which concerns on this invention is formed in the shape which each joining surface of the said two members fits together.

According to such a structure, the position of the two members of the state fitted in the joint surface is fixed. Thereby, since a drilling operation and a welding operation can be performed with high precision, a hole can be formed correctly in a predetermined drilling position. Moreover, it can melt | dissolve a hole reliably at the time of a welding operation.

Moreover, the manufacturing method of the turbine rotor which concerns on this invention is a method of manufacturing a turbine rotor by welding the 1st member and the 2nd member whose thermal conductivity differs from the said 1st member, and the said 1st, 2nd member And disposing one member so as to extend in the axial direction of the turbine rotor and one of the first and second members having higher thermal conductivity than the other member, and the first and second members. Forming a gas introduction hole for introducing gas into the turbine rotor at the bottom of the improvement portion for welding formed at the boundary of the through portion, and passing the bottom portion to the first member; And a step of welding the second member.

According to such a manufacturing method, when welding two members of a 1st member and a 2nd member face up and down, the heat | fever which generate | occur | produced at the time of the welding operation from a horizontal direction rises, and the member arrange | positioned at the upper side is located in the lower side. It is heated more strongly compared to the arranged member. However, the members disposed on the upper side have higher thermal conductivity as compared to the members disposed on the lower side, and dissipate more heat. For this reason, a big temperature difference does not generate | occur | produce in an upper member and a lower member, and the whole gas introduction hole can be reliably blocked at the time of a welding operation.

According to the turbine rotor according to the present invention, in a turbine rotor in which two different members are contacted and welded in the axial direction, an inert gas can be filled therein without degrading the quality of the turbine rotor after welding.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole block diagram which shows the steam turbine provided with the turbine rotor which concerns on 1st Embodiment of this invention.
2 is a schematic side view showing a part of a turbine rotor according to the first embodiment.
3 is a schematic cross-sectional view showing the periphery of an improved part in the turbine rotor of the first embodiment.
It is a schematic sectional drawing which shows the periphery of the improvement part in the turbine rotor of 2nd Embodiment.
It is a schematic sectional drawing which shows the periphery of the improvement part in the turbine rotor of 3rd embodiment.
6 is a diagram for explaining a problem that occurs when the boundary between two members is located at the center position of the improvement part.

(1st embodiment)

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the structure of the turbine rotor which concerns on 1st Embodiment of this invention is demonstrated. FIG. 1: is a whole block diagram which shows the steam turbine 1 provided with the turbine rotor 10 which concerns on 1st Embodiment. The steam turbine 1 includes a casing 2, an adjustment valve 3, a turbine rotor 10, a plurality of stator blades 4, a plurality of rotor blades 5, and a bearing portion 6. do. The adjustment valve 3 adjusts the amount and pressure of the steam S flowing into the casing 2. The turbine rotor 10 is rotatably installed inside the casing 2 and transmits power to machines such as a generator (not shown). The plurality of vanes 4 is provided on the inner circumferential surface of the casing 2. The plurality of rotor blades 5 are provided on the outer circumferential surface of the turbine rotor 10. The bearing part 6 supports the turbine rotor 10 rotatably around an axis.

2 is a schematic side view illustrating a part of the turbine rotor 10. The turbine rotor 10 is provided with the rotor main body 11, the welding part 12, and the cavity part 13. The rotor body 11 extends in the axial direction of the turbine rotor 10. The weld part 12 is provided in the axial direction predetermined position in the rotor main body 11. The cavity part 13 is formed in the rotor main body 11.

As shown in FIG. 2, the rotor body 11 includes a high hardness member (first member) 14 and a low hardness member (second member) 15. The high hardness member 14 has a substantially cylindrical shape and extends in the axial direction. The low hardness member 15 has a substantially cylindrical shape like the low hardness member 15 and extends in the axial direction.

The high hardness member 14 is a member having a relatively high hardness as compared with the low hardness member 15. As shown in FIG. 2, the high hardness member 14 is formed with a first notch 141 by cutting one end portion of the end portion in the radial direction in the longitudinal direction of the high hardness member 14.

The low hardness member 15 is a member having a relatively low hardness as compared with the high hardness member 14. Also in this low hardness member 15, as shown in FIG. 2, the 2nd cutout part 151 is formed by cutting one end part of the edge part in the radial direction in the longitudinal direction of the low hardness member 15. As shown in FIG. 2 and 3, the outer diameter of the second notch 151 is approximately equal to the outer diameter of the first notch 141 of the high hardness member 14 as shown in FIG. 2 and FIG. 3. Similarly, the length L1 of the 2nd notch 151 in the axial direction is formed longer than the length L2 of the 1st notch 141 in the axial direction.

Here, as the combination of the high hardness member 14 and the low hardness member 15, for example, as the high hardness member 14, 9% chromium steel (steel material containing 9% chromium, the same below) is used. On the other hand, as the low hardness member 15, you may use 2.25% chromium steel and 3.5% nickel steel. In addition, 12% chromium steel may be used as the high hardness member 14, and 2.25% chromium steel or 3.5% nickel steel may be used as the low hardness member 15. As shown in FIG. As the high hardness member 14, a nickel-based alloy may be used, while the low hardness member 15 may be 2.25% chromium steel, 9% chromium steel, or 12% chromium steel. In addition, stainless steel is used as the high hardness member 14, and as the low hardness member 15, 2.25% chromium steel, 9% chromium steel, or 12% chromium steel may be used. In addition, the combination of the high hardness member 14 and the low hardness member 15 is not limited to this, If it is a member with relatively different hardness, arbitrary combinations can be employ | adopted.

As shown in FIG. 2, the first cutout 141 of the high hardness member 14 and the second cutout 151 of the low hardness member 15 are combined to form an improvement portion 16. 3 is a schematic cross-sectional view showing the periphery of the improvement unit 16. As shown in FIG. 3A, the boundary 17 between the high hardness member 14 and the low hardness member 15 faces the groove width direction of the improved portion 16, and the center position C (in FIG. 3). It is positioned so as to be biased toward the side of the high hardness member 14 by a predetermined distance X than the dashed-dotted line shown).

The weld part 12 connects the high hardness member 14 and the low hardness member 15. As shown in FIG. 2, the welded part 12 is an improved part 16 formed by joining the first notch 141 and the second notch 151 to form a hard member using a welding torch T. FIG. It is formed by welding the 14 and the low hardness member 15.

The cavity part 13 is a space for filling inert gas which prevents oxidation of the wave 19 during a welding operation. As shown by the broken line in FIG. 2, this cavity 13 has the 1st recessed part 131 formed in the high hardness member 14, and the 2nd recessed part 132 formed in the low hardness member 15, It is formed by joining.

Next, the manufacturing method of the turbine rotor 10 which concerns on 1st Embodiment is demonstrated. First, the worker makes the high hardness member 14 and the low hardness member 15 contact. That is, as shown in FIG. 3A, the worker faces the first notch 141 and the second notch 151 to face one end of the high hardness member 14 and the low hardness member ( One end of 15) is contacted. Thereby, the improvement part 16 is formed by the 1st notch 141 and the 2nd notch 151. FIG. As described above, the length L1 in the axial direction of the second notch 151 is formed longer than the length L2 in the axial direction of the first notch 141. Therefore, the boundary 17 of the high hardness member 14 and the low hardness member 15 exists so that it may move to the side of the high hardness member 14 rather than the center position C in the groove width direction of the improvement part 16. As shown in FIG.

Next, the worker forms the gas introduction hole 18 in the bottom of the improvement part 16. That is, the operator sets the drill D to the center position C toward the groove width direction of the improvement part 16, as shown to Fig.3 (a), and the improvement part 16 as shown to Fig.3 (b). Penetrate the bottom of). At this time, the boundary 17 of the high hardness member 14 and the low hardness member 15 exists so that it may shift to the side of the high hardness member 14 rather than the center position C of the improvement part 16. As shown in FIG. Therefore, the drill D passes through the position deviating from the boundary 17 and penetrates the low hardness member 15 to form the gas introduction hole 18.

Thus, by passing the drill D out of the boundary 17, the problem that the gas introduction hole 18 is formed in the position which shifted from the original drilling position can be prevented beforehand. 6 is a diagram for explaining a problem that occurs when the boundary 17 is located at the center position C of the improvement unit 16. When the boundary 17 of two members 14 and 15 is located at the center position C of the improvement part 16, as shown to Fig.6 (a), it makes a hole with the drill D in the boundary 17. When attempting to drill a hole, the drill D slides off the boundary 17 and flows down. Thereby, it may be formed in the position shifted from the original punching position, as shown to FIG. 6 (b). In this case, as shown in FIG.6 (c), even if the welding operation of the two members 14 and 15 is performed, a part of the gas introduction hole 18 will remain unblocked. If a part of the gas introduction holes 18 remain in this manner, the inert gas inside the cavity 13 leaks out from the gas introduction holes 18, thereby oxidizing the wave 19 during welding. The problem that the strength of a weld part is lacking arises. In particular, when the groove width of the improvement part 16 is narrow, the perforation position of the gas introduction hole 18 and the boundary 17 of the two members 14 and 15 are the groove width of the improvement part 16. This problem is likely to occur because it is easy to match at the direction center position.

Moreover, such a problem becomes especially remarkable when the hardness of the two members 14 and 15 joined by welding differs. This is because, when the tip of the drill D inserted into the improved portion 16 to open the gas introduction hole 18 reaches the boundary 17 between the two members 14 and 15, the high hardness member 14 It is because it flows to the side of the low-hardness member 15 by being bounced by ().

Next, the operator introduces an inert gas into the cavity 13. That is, the worker fills the cavity 13 formed inside the rotor main body 11 with an inert gas such as argon gas through a tube (not shown) inserted through the gas introduction hole 18.

Next, the worker welds the high hardness member 14 and the low hardness member 15. That is, as shown in FIG. 2, an operator inserts the front end of the welding torch T to the improvement part 16 from the horizontal direction, and it is an example to the boundary 17 of the high hardness member 14 and the low hardness member 15, for example. For example, install TIG welding. Thereby, as shown in FIG.3 (c), the periphery of the boundary 17 melt | dissolves and the welding part 12 is formed, The high hardness member 14 and the low hardness member 15 are formed by this welding part 12. FIG. Are bonded to each other. At this time, the periphery of the gas introduction hole 18 near the boundary 17 is greened, so that the gas introduction hole 18 is sealed. And the part formed in the outer part of the rotor main body 11 of the welding part 12 is formed in the outer part of the rotor main body 11 of the welding part 12 by the inert gas (not shown) sprayed from the welding torch T. Oxidation of the part is prevented. On the other hand, the wave 19 formed in the rotor main body 11 of the welding part 12 is a wave inside the rotor main body 11 of the welding part 12 by the inert gas filled in the cavity part 13. Oxidation of the portion where 19 is formed is prevented. In addition, although the welding part 12 was shown only in the bottom part of the improvement part 16 in FIG.3 (c) for convenience of description, at the end of a welding operation, the welding part 12 is shown by the 2-point lane in the figure. Likewise, it is formed to a position to fill the entirety of the improvement part 16. The turbine rotor 10 is completed by the above.

(Second Embodiment)

Next, the structure of the turbine rotor 20 which concerns on 2nd Embodiment of this invention is demonstrated. The turbine rotor 20 of this embodiment differs only in the structure of the rotor main body 21 compared with the turbine rotor 10 of 1st Embodiment. Since the other structure and manufacturing method are the same as that of 1st Embodiment, the code | symbol same as 1st Embodiment is used, and description is abbreviate | omitted here.

4 is a schematic cross-sectional view showing the periphery of the improvement unit 16 in the turbine rotor 20 of the second embodiment. Although the rotor main body 21 of this embodiment is the same as the rotor main body 21 of 1st Embodiment in the point which has the high hardness member 14 and the low hardness member 15, the high hardness member 14 and the low hardness The shape of the joining surface of the member 15 is different. That is, as shown to Fig.4 (a), the stepped part 22 of step shape is formed in the one end part of the high hardness member 14. As shown to FIG. In addition, a stepped step portion 23 in a step shape is formed at one end of the low hardness member 15. The stepped portion 22 of the high hardness member 14 and the stepped portion 23 of the low hardness member 15 are fitted to each other. According to such a structure, when welding the high hardness member 14 and the low hardness member 15 as shown to FIG.3 (c), both members 14 and 15 in the position of the boundary 17 are shown. Is fixed in a state where the axes of each other are aligned without displacing each other in the radial direction. For this reason, the periphery of the gas introduction hole 18 can be melt | dissolved reliably, and the gas introduction hole 18 can be reliably sealed. In addition, similarly, even when the gas introduction hole 18 is drilled in the bottom part of the improvement part 16 by the drill D, both the members 14 and 15 are fixed in the state which mutually mutually aligned axes. For this reason, the gas introduction hole 18 can be formed in the center position C of the improvement part 16 correctly.

FIG. 4B is a diagram illustrating a modification of the second embodiment. In this modification, the convex portion 24 is formed at one end of the high hardness member 14, while the convex portion 24 of the high hardness member 14 is fitted to one end of the low hardness member 15. The recessed part 25 of the shape to match is formed. In addition, about the effect, it is the same as the fitting by the step part 22, 23 shown to Fig.4 (a).

FIG. 4C is a diagram illustrating another modified example of the second embodiment. In this modification, the concave portion 26 is formed at one end of the high hardness member 14, and the concave portion 26 of the high hardness member 14 is fitted to one end of the low hardness member 15. The convex part 27 of the shape to match is formed. In addition, about the effect, it is the same as the fitting by the step part 22, 23 shown to Fig.4 (a).

(Third Embodiment)

Next, the structure of the turbine rotor 30 which concerns on 3rd Embodiment of this invention is demonstrated. The turbine rotor 30 of this embodiment differs in the structure of the rotor main body 31, and its manufacturing method compared with the turbine rotor 10 of 1st embodiment. Since it is the same as that of 1st Embodiment about another point, the same code | symbol as 1st Embodiment is used, and description is abbreviate | omitted here.

FIG. 5: is schematic sectional drawing which shows the periphery of the improvement part 16 in the turbine rotor 30 of 3rd Embodiment. The rotor main body 31 of this embodiment is the same as the rotor main body 31 of 1st Embodiment by the point which has the high hardness member 14 and the low hardness member 15. As shown in FIG. However, the thermal conductivity of the high hardness member 14 and the low hardness member 15 is different from that of the first embodiment. In more detail, the thermal conductivity of the high hardness member 14 is relatively high, and the thermal conductivity of the low hardness member 15 is relatively low.

In manufacture of the turbine rotor 30 comprised in this way, as shown in FIG. 5, the worker has the low hardness member 15 with low thermal conductivity located in the lower side, and the high hardness member 14 with high thermal conductivity in the upper side. The tip ends of both the members 14 and 15 are brought into contact with each other. And the operator, like the first embodiment, forms the gas introduction holes 18 at the bottom of the improved portion 16, fills the inert gas into the cavity 13, and the high hardness member 14 and the low hardness. The turbine rotor 30 is manufactured by working in the order of welding of the member 15. FIG.

According to such a manufacturing method, as shown in FIG. 5, since the heat which generate | occur | produced at the time of the welding operation from the horizontal direction rises, the high hardness member 14 arrange | positioned at the upper side is the low hardness member 15 arrange | positioned at the lower side. In comparison with, it is heated more strongly. However, since the high hardness member 14 has a higher thermal conductivity as compared with the low hardness member 15 and emits more heat, as indicated by arrows Y1 and Y2 in FIG. 5, the high hardness member 14. And a large temperature difference do not occur between the low hardness member 15. Thereby, since the high hardness member 14 and the low hardness member 15 can be melt | dissolved uniformly at the time of carrying out the welding operation of the high hardness member 14 and the low hardness member 15, the gas introduction hole 18 is carried out. Can be reliably sealed.

In addition, in this embodiment, although the thermal conductivity of the high hardness member 14 was made relatively high and the thermal conductivity of the low hardness member 15 was relatively low, on the contrary, the thermal conductivity of the high hardness member 14 was made into It may be made relatively low, and the thermal conductivity of the low hardness member 15 may be made relatively high. In this case, in manufacture of the turbine rotor 30, the same effect as the above is obtained by arrange | positioning the high hardness member 14 with low thermal conductivity on the lower side, and the low hardness member 15 with high thermal conductivity on the upper side, respectively. Lose.

In addition, in each embodiment described above, the case where drill D flows especially is easy and the case where two different members which comprise the rotor main bodies 11, 21, and 31 are members with different hardness was demonstrated as an example, Not limited to this, two different members may be the same hardness.

In addition, the shape, the combination, the operation procedure, etc. of each structural member shown in embodiment mentioned above are an example, and various changes are possible based on a design request etc. in the range which does not deviate from the well-known of this invention.

1: steam turbine
2: Casing
3: regulating valve
4: stator
5: rotor
6: bearing part
10: turbine rotor
11:
12: welding part
13: joint department
14: high hardness member
15: low hardness member
16: improvement unit
17: boundary
18: hole for gas introduction
19: wave
20: turbine rotor
21: rotor body
22: stepped portion
23: step
24: convex
25: recess
26: recess
27: convex
30: turbine rotor
31: rotor body
131: first recessed portion
132: second recessed portion
141: first cutout
151: second cutout
C: center position
D: Drill
L1: Length (first cutout)
L2: Length (second cutout)
S: steam
T: welding torch
X: predetermined distance
Y1: arrow
Y2: arrow

Claims (5)

A first member,
It is a turbine rotor provided with the 2nd member joined to the said 1st member, and the said 1st, 2nd member extends to an axial direction,
The improvement part for welding is formed in the boundary of a said 1st, 2nd member, The gas introduction hole for introducing gas into the inside of the said turbine rotor penetrates the bottom part of the said improvement part, and is sealed by welding. , Turbine rotor. The method of claim 1, wherein the material of the first member is different from the second member,
The turbine rotor in which the boundary of the said 1st, 2nd member in the said improvement part exists in the biased position in either member. The method of claim 2, wherein the material of the first member is different from the second member,
The turbine rotor in which the said boundary exists in the 1st and 2nd member among the members with high hardness, and exists. The turbine rotor according to any one of claims 1 to 3, wherein each of the joining surfaces of the two members is formed in a shape to be fitted to each other. A method of manufacturing a turbine rotor by welding a first member and a second member having a different thermal conductivity from the first member,
Arranging the first and second members so that both members extend in the axial direction of the turbine rotor and one of the first and second members is higher than the other member; ,
Forming a gas introduction hole for introducing gas into the turbine rotor at the bottom of the improvement portion for welding formed at the boundary between the first and second members so as to penetrate the bottom;
And a step of welding the second member to the first member in the improved part.

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